1. Field of the Invention
The present invention relates generally to computer systems, and more particularly to an apparatus for using or accessing a plurality of host computers by using a PCB card edge connector to connect to the host computers.
2. Description of Related Art
In many applications, it is advantageous to interconnect a single computer to multiple computers. For example, a keyboard/video/mouse (“KVM”) switch is a device that is generally connected to multiple computers (“host computers”) in order to enable a single keyboard, video display monitor and mouse (the “user console”) to control each of the connected computers. Similarly, there also exists an enhanced version called a keyboard/video/mouse/audio (“KVMA”) switch that includes the ability to enable a single set of speakers to be selectively routed to each of the connected computers. In this way, a user may have access to multiple host computers without having to deal with the clutter and space requirements of having separate keyboard, monitor, and mouse for each of the computers. When the user accesses a host computer connected to the KVMA switch, video signals are routed from the computer, processed, and displayed on the single video monitor. Generally, to access another host computer, the user either physically actuates buttons or other mechanisms on the body of the KVMA switch. Some KVMA switches utilize software switching, wherein software is loaded on all of the host computers and a user selects an active host computer by pressing a combination of keys on the keyboard and/or clicking buttons on the mouse of the user console.
Regardless of the method of selecting the active host computer, there are many cables and wires for a computer user to connect between the KVMA switch and the host computers, as well as the cables for the interface devices. In particular, the cables that connect each host computer to the KVMA switch can include: a video cable, cursor control signal cable, a keyboard control signal cable, and audio out signal cable. Accordingly, with each host computer added to the KVMA switch, four additional cables are needed (three if USB type connectors are used). This can make things complicated for the non-technically savvy individual both when she initially sets-up a KVMA switch and if the user later wants to move a host computer or add additional ones.
One approach to simplify the setup of a KVMA switch utilizes a set of host computer cables integrated into the KVMA switch base, so that there are no connectors for the user to hook-up on one end of the host computer cables, as they simply extend from the KVMA switch base (“extending cables”). This approach does simplify the set-up of the KVMA switch for the user; however, there are several drawbacks to this approach. First, because the length of the extending cables is fixed by the manufacturer of the KVMA switch, the length can not be altered by the user. The manufacturer could offer the KVMA switch with several lengths of cables, but that would create excess inventory to deal with and the potential users would be forced to make a choice and stick with it for the life of the product. Second, if the user wants to later move one of his or her host computers to a different location, there is no way to lengthen or shorten the cables (short of hiring a technician to splice the cables—an expensive and inefficient approach that will likely causes signal loss and/or introduce noise into the cables as well). Third, a particular embodiment of the KVMA switch can control up to say four computers and the user only wants to control three, there will be an extra length of unused bulky cable to leave dangling from the KVMA switch.
Another approach to simplify the setup of a KVMA switch reduces the number of connectors attached from the KVMA body or housing to each host computer controlled by the KVMA switch, by combining the video signal, cursor control signal, and keyboard control signal cables into one video signal connector. This can be accomplished by utilizing the extra connection pins in the industry standard DB15 video signal connector utilized with video signals transmitted under the video graphics array (“VGA”) standard. A separate connector is still required for the audio out signal cable for each host computer. The use of the combined video signal, keyboard signal and cursor control signals into one custom designed, non-standard connector for each host computer does significantly reduce the number of cables and connectors required for hooking-up each host computer to the KVMA switch body, so that two connectors are required to control each host computer with the KVMA switch, thereby improving the ease of set-up for users, but there is still room for further improvement.
It is desirable, therefore, to provide a KVMA switch that is easy and quick to set-up, preferably having only one cable and connector that needs to be connected to the KVMA switch housing. Such an apparatus can have the added benefit of avoiding the introduction of noise and signal loss into the signal paths by minimizing the signal path length and the number of discrete internal connection wires utilized in attaching the host computers to the KVMA switch body. Additionally, such an apparatus could reduce the cost to the manufacturer, wholesaler, distributor, and to the end user.